Coupling



FIG. 1 is a perspective view of the coupling.

FIG. 2 is a front view of the coupling of FIG. 1.

FIG. 3 is a back view of the coupling of FIG. 1.

FIG. 4 is a right side view of the coupling of FIG. 1.

FIG. 5 is a left side view of the coupling of FIG. 1.

FIG. 6 is a top view of the coupling of FIG. 1; and,

FIG. 7 is a bottom view of the coupling of FIG. 1.

The evenly dashed broken lines illustrate portions of the coupling that form no part of the claim. 

CLAIM The ornamental design for a coupling, substantially as shown and described. 